Sound Issues on Dell Inspiron 9400/E1705

[forsaken502]

After replacing the motherboard on my Dell 9400 laptop I can't get the sound to work. When opening the lid, the laptop plays the correct sound, but that's all I can get out of it. I've tried all the drivers available on the Dell website but nothing seems to make any difference. Any help would be appericiated.

 

[forsaken502]

As a side note, the laptop originally came with Windows XP which was then upgraded to Windows Vista and the sound worked fine. After changing the motherboard Windows Vista was reinstalled, then XP was tried, and finally Windows 7 is installed. All three OS's exibit the same issues.